code: def planar(input_dim):
      """
      A helper function to create a :class:`~pyro.distributions.transforms.Planar`
      object for consistency with other helpers.
  
      :param input_dim: Dimension of input variable
      :type input_dim: int
  
      """
  
      return Planar(input_dim)
  
imports: import math
  from functools import partial
  import torch
  import torch.nn
  import torch.nn.functional
  from torch.distributions import Transform, constraints
  from pyro.nn import DenseNN
  from ..conditional import ConditionalTransformModule
  from ..torch_transform import TransformModule
  from ..util import copy_docs_from
label_desc: Use image node_id 1 for calling a global function with example usage: planar(input_dim) and returns: Planar